The present invention relates generally to cardiac monitoring, and more particularly, to the monitoring of cardiac pressures in a patient's heart to detect worsening heart failure.
Heart failure is a chronic condition for which there is no cure, but which can be slowed with early diagnosis and ongoing treatment to improve an individual's quality of life. Heart failure is the result of a weakened heart muscle that can no longer efficiently pump blood to meet the demands of the body. With heart failure, circulation is impaired and blood pressure increases in the heart.
For certain patients, it may be beneficial to chronically monitor various hemodynamic parameters in the patient's heart in an outpatient setting to detect worsening heart failure, thus allowing the physicians to adjust the patient's therapies to decrease the disease's progression and thus decrease the risk of death and the need for hospitalization. One device that allows such hemodynamic monitoring is the MEDTRONIC CHRONICLE Model 9520 Implantable Hemodynamic Monitor (IHM), which, when coupled with a pressure sensor located in the right ventricle of the heart, can be programmed to measure and record over time right ventricle (RV) systolic pressure, RV diastolic pressure, pulse pressure, pre-ejection interval (PEI), systolic time interval (STI), peak positive and negative dP/dt, estimated pulmonary artery diastolic pressure (ePAD), patient activity level, and heart rate.
Although the tracking of these individual hemodynamic parameters has proven helpful in treating patients, there remains a need for further indicators of worsening heart failure.